1178825Sdfr/* 2233294Sstas * Copyright (c) 1997 - 2003 Kungliga Tekniska H��gskolan 3233294Sstas * (Royal Institute of Technology, Stockholm, Sweden). 4233294Sstas * All rights reserved. 5178825Sdfr * 6233294Sstas * Redistribution and use in source and binary forms, with or without 7233294Sstas * modification, are permitted provided that the following conditions 8233294Sstas * are met: 9178825Sdfr * 10233294Sstas * 1. Redistributions of source code must retain the above copyright 11233294Sstas * notice, this list of conditions and the following disclaimer. 12178825Sdfr * 13233294Sstas * 2. Redistributions in binary form must reproduce the above copyright 14233294Sstas * notice, this list of conditions and the following disclaimer in the 15233294Sstas * documentation and/or other materials provided with the distribution. 16178825Sdfr * 17233294Sstas * 3. Neither the name of the Institute nor the names of its contributors 18233294Sstas * may be used to endorse or promote products derived from this software 19233294Sstas * without specific prior written permission. 20178825Sdfr * 21233294Sstas * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 22233294Sstas * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23233294Sstas * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24233294Sstas * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 25233294Sstas * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26233294Sstas * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27233294Sstas * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28233294Sstas * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29233294Sstas * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30233294Sstas * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31233294Sstas * SUCH DAMAGE. 32178825Sdfr */ 33178825Sdfr 34233294Sstas#include "gsskrb5_locl.h" 35178825Sdfr 36233294Sstas#ifdef HEIM_WEAK_CRYPTO 37178825Sdfr 38178825Sdfrstatic OM_uint32 39178825Sdfrverify_mic_des 40178825Sdfr (OM_uint32 * minor_status, 41178825Sdfr const gsskrb5_ctx context_handle, 42178825Sdfr krb5_context context, 43178825Sdfr const gss_buffer_t message_buffer, 44178825Sdfr const gss_buffer_t token_buffer, 45178825Sdfr gss_qop_t * qop_state, 46178825Sdfr krb5_keyblock *key, 47233294Sstas const char *type 48178825Sdfr ) 49178825Sdfr{ 50178825Sdfr u_char *p; 51233294Sstas EVP_MD_CTX *md5; 52178825Sdfr u_char hash[16], *seq; 53178825Sdfr DES_key_schedule schedule; 54233294Sstas EVP_CIPHER_CTX des_ctx; 55178825Sdfr DES_cblock zero; 56178825Sdfr DES_cblock deskey; 57178825Sdfr uint32_t seq_number; 58178825Sdfr OM_uint32 ret; 59178825Sdfr int cmp; 60178825Sdfr 61178825Sdfr p = token_buffer->value; 62178825Sdfr ret = _gsskrb5_verify_header (&p, 63178825Sdfr token_buffer->length, 64178825Sdfr type, 65178825Sdfr GSS_KRB5_MECHANISM); 66178825Sdfr if (ret) 67178825Sdfr return ret; 68178825Sdfr 69178825Sdfr if (memcmp(p, "\x00\x00", 2) != 0) 70178825Sdfr return GSS_S_BAD_SIG; 71178825Sdfr p += 2; 72178825Sdfr if (memcmp (p, "\xff\xff\xff\xff", 4) != 0) 73178825Sdfr return GSS_S_BAD_MIC; 74178825Sdfr p += 4; 75178825Sdfr p += 16; 76178825Sdfr 77178825Sdfr /* verify checksum */ 78233294Sstas md5 = EVP_MD_CTX_create(); 79233294Sstas EVP_DigestInit_ex(md5, EVP_md5(), NULL); 80233294Sstas EVP_DigestUpdate(md5, p - 24, 8); 81233294Sstas EVP_DigestUpdate(md5, message_buffer->value, message_buffer->length); 82233294Sstas EVP_DigestFinal_ex(md5, hash, NULL); 83233294Sstas EVP_MD_CTX_destroy(md5); 84178825Sdfr 85178825Sdfr memset (&zero, 0, sizeof(zero)); 86178825Sdfr memcpy (&deskey, key->keyvalue.data, sizeof(deskey)); 87178825Sdfr 88233294Sstas DES_set_key_unchecked (&deskey, &schedule); 89178825Sdfr DES_cbc_cksum ((void *)hash, (void *)hash, sizeof(hash), 90178825Sdfr &schedule, &zero); 91233294Sstas if (ct_memcmp (p - 8, hash, 8) != 0) { 92178825Sdfr memset (deskey, 0, sizeof(deskey)); 93178825Sdfr memset (&schedule, 0, sizeof(schedule)); 94178825Sdfr return GSS_S_BAD_MIC; 95178825Sdfr } 96178825Sdfr 97178825Sdfr /* verify sequence number */ 98233294Sstas 99178825Sdfr HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex); 100178825Sdfr 101178825Sdfr p -= 16; 102178825Sdfr 103233294Sstas EVP_CIPHER_CTX_init(&des_ctx); 104233294Sstas EVP_CipherInit_ex(&des_ctx, EVP_des_cbc(), NULL, key->keyvalue.data, hash, 0); 105233294Sstas EVP_Cipher(&des_ctx, p, p, 8); 106233294Sstas EVP_CIPHER_CTX_cleanup(&des_ctx); 107233294Sstas 108178825Sdfr memset (deskey, 0, sizeof(deskey)); 109178825Sdfr memset (&schedule, 0, sizeof(schedule)); 110178825Sdfr 111178825Sdfr seq = p; 112178825Sdfr _gsskrb5_decode_om_uint32(seq, &seq_number); 113178825Sdfr 114178825Sdfr if (context_handle->more_flags & LOCAL) 115233294Sstas cmp = ct_memcmp(&seq[4], "\xff\xff\xff\xff", 4); 116178825Sdfr else 117233294Sstas cmp = ct_memcmp(&seq[4], "\x00\x00\x00\x00", 4); 118178825Sdfr 119178825Sdfr if (cmp != 0) { 120178825Sdfr HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); 121178825Sdfr return GSS_S_BAD_MIC; 122178825Sdfr } 123178825Sdfr 124178825Sdfr ret = _gssapi_msg_order_check(context_handle->order, seq_number); 125178825Sdfr if (ret) { 126178825Sdfr HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); 127178825Sdfr return ret; 128178825Sdfr } 129178825Sdfr 130178825Sdfr HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); 131178825Sdfr 132178825Sdfr return GSS_S_COMPLETE; 133178825Sdfr} 134233294Sstas#endif 135178825Sdfr 136178825Sdfrstatic OM_uint32 137178825Sdfrverify_mic_des3 138178825Sdfr (OM_uint32 * minor_status, 139178825Sdfr const gsskrb5_ctx context_handle, 140178825Sdfr krb5_context context, 141178825Sdfr const gss_buffer_t message_buffer, 142178825Sdfr const gss_buffer_t token_buffer, 143178825Sdfr gss_qop_t * qop_state, 144178825Sdfr krb5_keyblock *key, 145233294Sstas const char *type 146178825Sdfr ) 147178825Sdfr{ 148178825Sdfr u_char *p; 149178825Sdfr u_char *seq; 150178825Sdfr uint32_t seq_number; 151178825Sdfr OM_uint32 ret; 152178825Sdfr krb5_crypto crypto; 153178825Sdfr krb5_data seq_data; 154178825Sdfr int cmp, docompat; 155178825Sdfr Checksum csum; 156178825Sdfr char *tmp; 157178825Sdfr char ivec[8]; 158233294Sstas 159178825Sdfr p = token_buffer->value; 160178825Sdfr ret = _gsskrb5_verify_header (&p, 161178825Sdfr token_buffer->length, 162178825Sdfr type, 163178825Sdfr GSS_KRB5_MECHANISM); 164178825Sdfr if (ret) 165178825Sdfr return ret; 166178825Sdfr 167178825Sdfr if (memcmp(p, "\x04\x00", 2) != 0) /* SGN_ALG = HMAC SHA1 DES3-KD */ 168178825Sdfr return GSS_S_BAD_SIG; 169178825Sdfr p += 2; 170178825Sdfr if (memcmp (p, "\xff\xff\xff\xff", 4) != 0) 171178825Sdfr return GSS_S_BAD_MIC; 172178825Sdfr p += 4; 173178825Sdfr 174178825Sdfr ret = krb5_crypto_init(context, key, 175178825Sdfr ETYPE_DES3_CBC_NONE, &crypto); 176178825Sdfr if (ret){ 177178825Sdfr *minor_status = ret; 178178825Sdfr return GSS_S_FAILURE; 179178825Sdfr } 180178825Sdfr 181178825Sdfr /* verify sequence number */ 182178825Sdfr docompat = 0; 183178825Sdfrretry: 184178825Sdfr if (docompat) 185178825Sdfr memset(ivec, 0, 8); 186178825Sdfr else 187178825Sdfr memcpy(ivec, p + 8, 8); 188178825Sdfr 189178825Sdfr ret = krb5_decrypt_ivec (context, 190178825Sdfr crypto, 191178825Sdfr KRB5_KU_USAGE_SEQ, 192178825Sdfr p, 8, &seq_data, ivec); 193178825Sdfr if (ret) { 194178825Sdfr if (docompat++) { 195178825Sdfr krb5_crypto_destroy (context, crypto); 196178825Sdfr *minor_status = ret; 197178825Sdfr return GSS_S_FAILURE; 198178825Sdfr } else 199178825Sdfr goto retry; 200178825Sdfr } 201178825Sdfr 202178825Sdfr if (seq_data.length != 8) { 203178825Sdfr krb5_data_free (&seq_data); 204178825Sdfr if (docompat++) { 205178825Sdfr krb5_crypto_destroy (context, crypto); 206178825Sdfr return GSS_S_BAD_MIC; 207178825Sdfr } else 208178825Sdfr goto retry; 209178825Sdfr } 210178825Sdfr 211178825Sdfr HEIMDAL_MUTEX_lock(&context_handle->ctx_id_mutex); 212178825Sdfr 213178825Sdfr seq = seq_data.data; 214178825Sdfr _gsskrb5_decode_om_uint32(seq, &seq_number); 215178825Sdfr 216178825Sdfr if (context_handle->more_flags & LOCAL) 217233294Sstas cmp = ct_memcmp(&seq[4], "\xff\xff\xff\xff", 4); 218178825Sdfr else 219233294Sstas cmp = ct_memcmp(&seq[4], "\x00\x00\x00\x00", 4); 220178825Sdfr 221178825Sdfr krb5_data_free (&seq_data); 222178825Sdfr if (cmp != 0) { 223178825Sdfr krb5_crypto_destroy (context, crypto); 224178825Sdfr *minor_status = 0; 225178825Sdfr HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); 226178825Sdfr return GSS_S_BAD_MIC; 227178825Sdfr } 228178825Sdfr 229178825Sdfr ret = _gssapi_msg_order_check(context_handle->order, seq_number); 230178825Sdfr if (ret) { 231178825Sdfr krb5_crypto_destroy (context, crypto); 232178825Sdfr *minor_status = 0; 233178825Sdfr HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); 234178825Sdfr return ret; 235178825Sdfr } 236178825Sdfr 237178825Sdfr /* verify checksum */ 238178825Sdfr 239178825Sdfr tmp = malloc (message_buffer->length + 8); 240178825Sdfr if (tmp == NULL) { 241178825Sdfr krb5_crypto_destroy (context, crypto); 242178825Sdfr HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); 243178825Sdfr *minor_status = ENOMEM; 244178825Sdfr return GSS_S_FAILURE; 245178825Sdfr } 246178825Sdfr 247178825Sdfr memcpy (tmp, p - 8, 8); 248178825Sdfr memcpy (tmp + 8, message_buffer->value, message_buffer->length); 249178825Sdfr 250178825Sdfr csum.cksumtype = CKSUMTYPE_HMAC_SHA1_DES3; 251178825Sdfr csum.checksum.length = 20; 252178825Sdfr csum.checksum.data = p + 8; 253178825Sdfr 254234027Sstas krb5_crypto_destroy (context, crypto); 255234027Sstas ret = krb5_crypto_init(context, key, 256234027Sstas ETYPE_DES3_CBC_SHA1, &crypto); 257234027Sstas if (ret){ 258234027Sstas *minor_status = ret; 259234027Sstas return GSS_S_FAILURE; 260234027Sstas } 261234027Sstas 262178825Sdfr ret = krb5_verify_checksum (context, crypto, 263178825Sdfr KRB5_KU_USAGE_SIGN, 264178825Sdfr tmp, message_buffer->length + 8, 265178825Sdfr &csum); 266178825Sdfr free (tmp); 267178825Sdfr if (ret) { 268178825Sdfr krb5_crypto_destroy (context, crypto); 269178825Sdfr *minor_status = ret; 270178825Sdfr HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); 271178825Sdfr return GSS_S_BAD_MIC; 272178825Sdfr } 273178825Sdfr HEIMDAL_MUTEX_unlock(&context_handle->ctx_id_mutex); 274178825Sdfr 275178825Sdfr krb5_crypto_destroy (context, crypto); 276178825Sdfr return GSS_S_COMPLETE; 277178825Sdfr} 278178825Sdfr 279178825SdfrOM_uint32 280178825Sdfr_gsskrb5_verify_mic_internal 281178825Sdfr (OM_uint32 * minor_status, 282233294Sstas const gsskrb5_ctx ctx, 283178825Sdfr krb5_context context, 284178825Sdfr const gss_buffer_t message_buffer, 285178825Sdfr const gss_buffer_t token_buffer, 286178825Sdfr gss_qop_t * qop_state, 287233294Sstas const char * type 288178825Sdfr ) 289178825Sdfr{ 290178825Sdfr krb5_keyblock *key; 291178825Sdfr OM_uint32 ret; 292178825Sdfr krb5_keytype keytype; 293178825Sdfr 294233294Sstas if (ctx->more_flags & IS_CFX) 295233294Sstas return _gssapi_verify_mic_cfx (minor_status, ctx, 296233294Sstas context, message_buffer, token_buffer, 297233294Sstas qop_state); 298233294Sstas 299233294Sstas HEIMDAL_MUTEX_lock(&ctx->ctx_id_mutex); 300233294Sstas ret = _gsskrb5i_get_token_key(ctx, context, &key); 301233294Sstas HEIMDAL_MUTEX_unlock(&ctx->ctx_id_mutex); 302178825Sdfr if (ret) { 303178825Sdfr *minor_status = ret; 304178825Sdfr return GSS_S_FAILURE; 305178825Sdfr } 306178825Sdfr *minor_status = 0; 307178825Sdfr krb5_enctype_to_keytype (context, key->keytype, &keytype); 308178825Sdfr switch (keytype) { 309178825Sdfr case KEYTYPE_DES : 310233294Sstas#ifdef HEIM_WEAK_CRYPTO 311233294Sstas ret = verify_mic_des (minor_status, ctx, context, 312178825Sdfr message_buffer, token_buffer, qop_state, key, 313178825Sdfr type); 314233294Sstas#else 315233294Sstas ret = GSS_S_FAILURE; 316233294Sstas#endif 317178825Sdfr break; 318178825Sdfr case KEYTYPE_DES3 : 319233294Sstas ret = verify_mic_des3 (minor_status, ctx, context, 320178825Sdfr message_buffer, token_buffer, qop_state, key, 321178825Sdfr type); 322178825Sdfr break; 323178825Sdfr case KEYTYPE_ARCFOUR : 324178825Sdfr case KEYTYPE_ARCFOUR_56 : 325233294Sstas ret = _gssapi_verify_mic_arcfour (minor_status, ctx, 326178825Sdfr context, 327178825Sdfr message_buffer, token_buffer, 328178825Sdfr qop_state, key, type); 329178825Sdfr break; 330178825Sdfr default : 331233294Sstas abort(); 332178825Sdfr } 333178825Sdfr krb5_free_keyblock (context, key); 334233294Sstas 335178825Sdfr return ret; 336178825Sdfr} 337178825Sdfr 338233294SstasOM_uint32 GSSAPI_CALLCONV 339178825Sdfr_gsskrb5_verify_mic 340178825Sdfr (OM_uint32 * minor_status, 341178825Sdfr const gss_ctx_id_t context_handle, 342178825Sdfr const gss_buffer_t message_buffer, 343178825Sdfr const gss_buffer_t token_buffer, 344178825Sdfr gss_qop_t * qop_state 345178825Sdfr ) 346178825Sdfr{ 347178825Sdfr krb5_context context; 348178825Sdfr OM_uint32 ret; 349178825Sdfr 350178825Sdfr GSSAPI_KRB5_INIT (&context); 351178825Sdfr 352178825Sdfr if (qop_state != NULL) 353178825Sdfr *qop_state = GSS_C_QOP_DEFAULT; 354178825Sdfr 355233294Sstas ret = _gsskrb5_verify_mic_internal(minor_status, 356178825Sdfr (gsskrb5_ctx)context_handle, 357178825Sdfr context, 358178825Sdfr message_buffer, token_buffer, 359233294Sstas qop_state, (void *)(intptr_t)"\x01\x01"); 360178825Sdfr 361178825Sdfr return ret; 362178825Sdfr} 363